He deliberately avoided mentioning Mr Corbyn by name during his thunderous address.

But the former Prime Minister called on Labour to adopt the International Holocaust Remembrance Alliance definition of anti-Semitism “unanimously, unequivocally and immediately”.

He said: "The declaration is about this and this only: to condemn and root out, as they state, anti-Semitism, which 'is a certain perception of Jews, which may be expressed as hatred toward Jews'.

"And this declaration is needed now, urgently. Not as some sort of abstract document of philosophy.

"It is needed now to deal with practical threats to confront gathering dangers and on-the-ground realities of very real week-by-week threats to Jewish communities that demand an unequivocal response and unqualified resolve."